Since the entire Servo team was laid off, I can image the c-suites planning a future move to Chromium. If Mozilla doesn't clean up its act, in a few years from now all browsers will be Chrome in different packaging (except Safari).
That said, there is a bright side of a browser engine monoculture: JavaScript will finally meet its very long-overdue demise. Google could implement Dart or an evolution of that language (they tried this around 2010, but Blink wasn't on 95% of [desktop] computers back then) and kill off JS overnight, since if every browser supports it by default, there's no reason not to use it over JS.
The massive downside, of course, is that Google also has the ability to design its browser so that extensions that perform adblocking can't run, and that'll be everywhere too- though I suspect that the number of people who would pay the price of a VPN connection a month for a modern browser with guaranteed ad-blocking support is quite large provided there's no other choice.